1. Field of the Invention
The present invention relates in general to the field of medical devices. More specifically, the present invention relates to the field of intravenous medical devices.
2. Description of Related Art
Intravenous catheter systems (IVs) are a staple technology in the field of administering medical care. While typical needles and syringes are capable of administering or drawing fluids to and from a patient's blood vessels, an IV allows for multiple administrations or drawings on the patient through the use of a single puncture to a chosen blood vessel. IVs also allow continuous administration or drawing of fluids, allowing convenient lengthy fluid administrations or drawings.
Blood spillage is currently a major problem when administering IVs. Spilled blood often contacts the patient, the patient's clothing and bedding, the medical caregiver, other medical devices nearby, and the floor. Blood spillage can pose significant health risks to the patient, medical caregivers, and janitorial service providers who ultimately dispose of the spilled blood. The risks associated with blood spillage stem from the communicable nature of many diseases and conditions which may use the spilled blood as a vehicle for transmission. Medical caregivers and janitorial service providers must take special precautions to protect themselves against the ill effects of communicable diseases in spilled blood by wearing protective gloves, eyewear, and other items of blood repellant clothing. This adds time, cost, and risk to what should be a simple procedure.
A typical IV comprises two separate portions, a retractable needle system and a catheter system. The retractable needle system commonly comprises a needle having a beveled tip, a housing into which the needle may be fully retracted, and a mechanism for manually or automatically retracting the needle into the housing. A common retractable needle system incorporates a spring-biased mechanism to accomplish needle retraction with the push of a button. Retractable needle systems are typically single-use devices that come packaged with a needle protruding from the housing. A protective cap is usually used to cover the protruding needle to both prevent the needle from becoming contaminated and also to minimize the safety risks associated with having an exposed needle.
The catheter system commonly comprises a hub portion having an attached catheter. The hub portion includes a means for connecting the catheter system to the retractable needle system. The hub portion is typically adapted to allow the insertion of the needle through the catheter and to form a seal with the housing of the retractable needle system. The hub also serves as a mechanism to connect the catheter with a luer-lock device.
The following steps are typically taken by a medical caregiver when placing an IV catheter. First, a tourniquet is placed on the selected limb. Then, the medical caregiver sterilizes the needle entry area on the patient with an antibacterial preparation. The needle entry area is usually the skin covering a chosen blood vessel near the surface of the skin. Next, the medical caregiver removes the protective cap from the needle, exposing the needle and the beveled tip which is protruding from the catheter. Then, the medical caregiver grasps an area slightly distal to the needle entry area and uses her thumb to both keep the skin taut and to anchor the chosen blood vessel.
Next, holding the needle at approximately a 45° angle with respect to the relatively flat needle entry area, and holding the beveled tip of the needle up away from the patient's skin, the medical caregiver pierces the patient's skin and tissue over the chosen blood vessel. It is important that the needle be inserted with the beveled side up in order to reduce entry resistance and trauma caused by the puncture. Then, the shaft of the needle is lowered toward the patient's skin until it is almost parallel with the skin surface. Next, the needle is advanced approximately one eighth of an inch into the blood vessel. Then, while holding the retractable needle system steady, the medical caregiver pushes the catheter into the blood vessel by manually sliding the hub portion and catheter away from the retractable needle system along the length of the needle.
Next, the medical caregiver slowly separates the needle retraction system from the catheter system by pulling back on the needle retraction system. This causes the needle to be removed from the catheter and the patient. As the seal between the hub portion and the housing is broken, it is necessary that the medical caregiver apply sufficient pressure slightly over the blood vessel and the catheter. This application of pressure is a means of preventing blood from passing through the catheter and spilling out of the open end of the hub portion. Once the needle is fully removed from the patient, the medical caregiver retracts the needle into the housing by activating the needle retraction mechanism and disposes of retractable needle system. Next, while continuing to apply pressure to the inserted catheter and the blood vessel, any previously applied tourniquet is released. Once the catheter is properly inserted into the blood vessel, additional accessories, including accessories to prevent the spillage of blood, are connected to the hub portion. These accessories allow fluids to be administered or drawn through the IV through various types of needles and devices, including needles, blunts, needleless syringes, IV bags, and automated medical pumping systems.
Blood spillage most often occurs while the retractable needle system is being separated from the catheter system and removed from the patient. This is because the medical caregiver must perform several tasks simultaneously while maintaining sufficient pressure on the catheter and blood vessel. Usually, these tasks must be performed with only one hand, and often while the patient is squirming or moving due to the pain of the catheter placement. This IV insertion process is difficult to perform, even with a well-behaved patient. The difficulty is increased when the patient will not or cannot be still. For example, placing an IV to a child can be extremely difficult. Children often do not understand the importance of remaining stationary during the procedure. Similarly, emergency or trauma patients may be unable to remain stationary during the placement of an IV. Complications resulting from the patient moving during the administration of the IV can range from mere annoyances to major health risks for both the patient and the medical caregiver.
Another shortcoming of current IVs presents itself during the separation of the retractable needle system from the catheter system. During that step, there exists a risk that the medical care giver may apply too much pressure causing undue pain to the patient or damaging the catheter or the blood vessel.
Fragmenting of the catheter may also occur when, during the removal of the needle from the catheter, the needle changes direction and is further advanced into the catheter. This reversal of direction of the needle can cause the sharp tip of the needle to tear off a fragment of the catheter. This phenomenon is commonly referred to as “catheter shearing.” Catheter shearing is a significant risk, because current IVs allow reentry of the needle into the catheter. If the needle punctures the catheter, a small portion of the catheter may become separated as a fragment from the catheter. If this small fragment enters the blood stream it can pose significant health risks, such as forming blood clots.
Some IVs incorporate a flash chamber. The flash chamber is a receptacle into which blood initially flows upon introducing the needle into a blood vessel. The purpose of the flash chamber is to notify the medical caregiver that the needle has punctured a blood vessel. While current flash chambers are helpful as an indicator, they are poorly located within the retractable needle system. The flash chamber is several inches away from the tip of the needle and usually obstructed from view by the caregiver's own hand. This placement requires the medical caregiver to visually monitor both the introduction of the needle into the blood vessel and the state of the flash chamber. Unfortunately, while the medical caregiver's attention is diverted to the flash chamber, the likelihood that the caregiver will move the needle in an undesirable manner, thereby causing unnecessary pain or injury to the patient, is increased. Likewise, while medical caregivers divert their attention to the introduction of the needle into the blood vessel, the medical caregivers are less likely to see that the flash chamber has filled with blood. If the medical caregiver is not notified of this, the medical caregiver may unnecessarily retract the needle from a successful insertion into the blood vessel causing unnecessary pain and injury.
A further shortcoming of current IVs is that the retractable needle systems allow undesirable movement of the device with respect to the needle entry area. Even small movements of the retractable needle system and the attached catheter can cause the patient pain.
Another problem with current IVs is that the catheter is not adequately flexible. This problem is particularly prevalent when the catheter is inserted into an articulating portion of patient's body, such as the ante-cubital space of the forearm. When the patient articulates the associated joint, the catheter presses against the walls of the blood vessel, causing the patient to experience pain. Also, bending of conventional catheters can cause the catheter to crease, kink, and split, resulting in diminished fluid flow and sharp edges on catheter.
Additionally, many current IVs present problems with dead-space. Dead-space is the volume within an IV that must be filled with fluid before the fluid can flow into the patient's blood vessel. Catheter systems hubs and catheters having large amounts of dead-space present several major problems: (1) when administering very small amounts of medication to the patient through an IV, the volume of dead-space may retain a significant portion of the medication, causing a delay in the patient receiving the medication; (2) blood tends to pool and coagulate in the dead-space, resulting in blood clots that can hinder or completely obstruct fluid flow; and (3) injection of medication is more time-consuming.
Another major shortcoming of conventional IVs is that they do not allow the use of conventional needles, blunt devices, Luer lock devices, and other needleless devices all on the same IV system.
Thus, while there are many types of IV systems currently in use, considerable shortcomings remain.